A)virion.
B)provirus.
C)plasmid.
D)phage.
E)prion.

A)a type of virus which causes neurodegenerative diseases in humans and animals.
B)an infective protein that causes encephalitis.
C)easily destroyed by most disinfectants.
D)responsible for infections in animals but not humans.
E)easily transmissible from person to person.

A)infects one or a limited number of tissue types.
B)attaches to numerous cell types,but only infects one type.
C)is always able to cross the species barrier.
D)is resistant to host defence mechanisms in that tissue.
E)always causes life-threatening infections.